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What is the correct procedure to put the software in speed-density mode for a MAF delete?

Set MAF Frequency Fail High to 0 Hz, set P0101, P0102, and P0103 to report on first error with the SES light unchecked, and keep the MAF plugged in so the IAT still reads. The ECM then treats the MAF as failed and fuels from the VE (or VVE / Boost VE) tables. On P01/P59 use the 2-bar/3-bar custom OS for boost, on E40 use the 2.5-bar OS, and on E38/E67 just scale the MAP linear/offset — never set the MAF DTCs to No Error Reported, because that keeps the MAF enabled and the ECM never enters speed density.

Last updated October 10, 2026

Who this applies to

Computers: P01, P59, E40, E38, E67
Engines: LS1, LS6, LM7, LQ4, LQ9, LS2, LS3, LS7
Transmissions: all
Years: 1997-2013
Not for: Gen V E92/E92A (different procedure, not covered here)

Gen III P01/P59, stock or custom OS, HP Tuners

Engine Diagnostics > Airflow > MAF Frequency Fail High: set to 0 Hz
Engine Diagnostics > DTCs: set P0101, P0102, P0103 to 'MIL on First Error' (No MIL Light), uncheck the SES box so no dash light shows MIL on First Error, SES unchecked
Alternative on older OS years: Engine > Airflow > Dynamic > Steady State — set Lo/Hi MAP and Lo/Hi TPS to 0 to force VE-only
Keep the MAF plugged in if it carries the IAT; do not unplug the sensor

Gen IV E38/E67, HP Tuners

Engine Diagnostics > Airflow > Mass Airflow Sensor > MAF Frequency Fail High: set to 0 Hz
Engine Diagnostics > DTCs: P0101/P0102/P0103 to 'MIL on First Error', SES unchecked — never 'No Error Reported' or SD never engages
Fail P0102/P0103 — those are the DTCs that trigger SD, not P0101

Boosted: P01/P59 or E40, HP Tuners custom OS

P01/P59: apply the 2-bar or 3-bar Speed Density OS (OS tab, Write Entire) — SD mode only 2-bar or 3-bar SD OS
E40: apply the 2.5-bar Speed Density OS — adds a Boost VE table from 105-255 kPa (22.5 psi boost), SD mode only

Careful

Write Entire is required for an OS change — a failed full write can brick a Gen III PCM. Keep the battery fully charged and the charger unplugged during the write.
Don't tune the VE table until SD is confirmed engaged — with the MAF still active, corrections won't behave.

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Go deeper

Check this first

Log MAF frequency — if the sensor still reads airflow and no P0102/P0103 sets, SD is not engaged
Check the MAF DTC modes — 'No Error Reported' means the ECM never enters SD

Try this, then this

Set MAF Frequency Fail High to 0 Hz and P0101/P0102/P0103 to MIL on First Error with SES unchecked — The canonical fail-in-software path; no wiring change needed. Worked if: P0102/P0103 set and VE drives fueling
Set Engine > Airflow > Dynamic > Steady State Lo/Hi MAP and Lo/Hi TPS to 0 — Forces VE-only on OS years where fail frequency alone doesn't stick. Worked if: VE-only fueling confirmed in the log
Apply the matching custom SD OS (1-bar Enhanced, 2-bar, 3-bar, or 2.5-bar E40) with Write Entire — Stock OS can glitch back toward MAF; the custom OS is SD-only. Worked if: SD engages immediately with no hunting

How you know it's fixed

P0102 and/or P0103 set on the first key cycle and fueling follows the VE table
Scanner shows the MAF as failed while the engine runs off VE

Key numbers

What	Value
MAF Frequency Fail High setting that forces SD	0 Hz
DTC mode that defeats SD	'No Error Reported' keeps the MAF enabled
DTCs that actually trigger SD	P0102 and P0103
IAT reading if the 5-wire MAF is unplugged	defaults to -40
Steady-state VE-only alternative	Lo/Hi MAP and Lo/Hi TPS to 0
2.5-bar E40 SD OS boost VE range	105-255 kPa (2.5 bar / 22.5 psi boost)

Time and cost: Free in software (covered by the VIN license/credits you already have); about 30 minutes to fail the MAF, reflash, and confirm.

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